Abstract :
AT this time, when the incandescent electric lamp is perhaps at the zenith of its career, there is a certain propriety in recording its status, in appraising it as an illuminant, and in reviewing the circumstances surrounding its production and use. As an instrument in the advance of civilization, the lamp is highly important. In its technical and economic relationships it has been, and is, the subject of intensive engineering study. Thereby has come benefit to the art of illumination, which it serves well, and to the public welfare, to which it has made large contributions. Incidentally, the lamp illustrates the process of transformation of a luxury through intensive and widespread use into a necessity. Somewhat of an assay of the incandescent lamp being proposed, it has seemed in order for the writer to undertake it because for several decades, though connected with neither a manufacturer of lamps nor an electric light and power company, he has had continuing contacts with both through independent lamp testing services. This circumstance accounts for an unusually comprehensive acquaintance with developments in lamp engineering. In this respect, this paper may be considered a sequel to an Institute paper presented in 1936 entitled, “The Qualities of Incandescent Lamps.”1
